Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
nganh xay » nganh mac, nganh y, nganh ma
xay thuat » ky thuat, my thuat, cac thuat
toan hoc » toan khoa, van hoc, hoa hoc
va thuat » ky thuat, va thuc, va thiet
ki thuat » ky thuat
vu sach » vu bach, su sach, vu khach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu sach nganh xay thuat toan hoc ) or ( vu sach nganh ((va thuat) OR (ki thuat)) toan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach nganh xay thuat toan hoc ) OR ( vu sach nganh ((va thuat) OR (ki thuat)) toan hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu sach nganh xay thuat toan hoc ) or ( vu sach nganh ((va thuat) OR (ki thuat)) toan hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( vu sach nganh xay thuat toan hoc ) or ( vu sach nganh ((va thuat) OR (ki thuat)) toan hoc ))*.